1. Field of the Invention
This invention relates to fences, especially those to be used for visual barriers, for decorative effect, for animal containment, for light-duty crowd control, and for a variety of other functions where this contemporary and abstracted equivalent of a split-rail fence might be used. This invention is a condensation and simplification of the components and connections from which fences are made.
2. Description of Prior Art
Heretofore, fences have been designed to be installed using posts of pre-cut lengths, which are designed to accept prefabricated fence panels or panel material (such as woven wire chain-link fence "cloth") which come in a limited number of predetermined widths. These fence posts and panels, or rails, are then connected by a variety of hardware components (such as u-bolts, clamps, to fit end-posts of panels to be mounted, etc.) or by the fitting together of posts and panels by the geometry of pegs, projections, rails, or end-posts with receiving holes, slots, or other configurations. One odor art fence is designed to be assembled from a kit of parts fabricated to work to together in a fence system. These fence systems are usually too complicated for the average user to assemble and are commonly installed by commercial distributors and fence specialists who also sell the components.
All fences are modular in that they are made up of a limited number of structural components used repetitively. A modular fence system is desirable if it has a combination of characteristics including the following: low initial cost of parts, lightweight components of small size and therefore easily transported and handled; easily and quickly assembled at the site by unskilled labor; requiring the fewest possible subassemblies or components to constitute a complete system; capable of being assembled into a wide variety of sizes and configurations; capable of extension of reduction of height or length; capable of being reinforced as needed to increase strength to meet loading requirements; capable of being converted between any two posts to a gate; capable of disassembly without destruction of fence panels and posts for re-use elsewhere; and being aesthetically attractive.
All of the foregoing are desirable, if not necessary, of maximum performance in a fence system and hence for value to the fence owner. Prior art fences, "modular" or not, have fallen short on one or more of the above characteristics, even though their general desirability was recognized.
For support and anchorage, most fence posts require several feet of length, beyond what will be above ground, to go into the earth or a concrete footing. This extra length (and weight) adds difficulty to transpod, handling, and it adds cost. Posts are commonly made in standard lengths: if the user needs a different length, he must cut off and waste materials, or he must pay a premium price for a custom length. Most prefabricated fence panels tend to be large, heavy, and/or awkward to handle. There is no easy way to vary the length of such panels to fit dimensions in the field. Panel materials are usually fabricated in a limited variety of lengths for the manufacturer's convenience and economy of production, and for competitive pricing. Most users have, until now, had to rely on sellers or contractors for pads, installation, and service. Installation by the fence supplier, or by a third-party contractor, usually increases the owner's cost, per linear foot of fence, by a factor of two or more.
One prior art fence, the "Modular Fence System" (U.S Pat. No. 4,498,660), comprises individual louver blade modules (affording visual privacy while maintaining free airflow.) Each louver module is an element of both fence post and fence panel and comprises a single, sloped, louver blade having at opposite ends, alternating, offset cylinders of 1/2 the louver-module height, such that consecutive louvers can be joined at their ends, threaded over prefabricated posts, pipes, or rods which link the louvers in a structural, pin-connection. Louvers may be of any length and may be arranged in any continuous, linear, polygonal layout as long as the louver-linkage continuity is maintained. Disadvantages in this system include the lack of provision for any kind of opening or gate in the fence (other than a fence discontinuation,) virtually no adaptability to changes in terrain elevation or slopes, and no provision for three- or four-way fence intersections (as at corners of adjoining properties) without disruption of the vertical spacing between louvers.
Another prior art fence, the "Fence" (U.S. Pat. No. 4,174,096,), comprises complete panel modules, with end extensions similar to those cited above, which may be formed in any continuous, straight, zig-zag, or polygonal configuration, by making vertical pin-connections between consecutive panels. The panel modules are to be pin-connected with pipes, posts, or rods. Some of the same disadvantages described above apply to this system. There is no separate "post" in this system. The complete panels represented in the "Fence" patent could be awkward to handle due their size and/or weight (a typical fence layout has posts set eight feet apart.) This system can be set up to form multi-fence intersections, but the spacing of the louvers would be changed and the privacy provided by the louvers would be lost if branching to create new fence runs were attempted. There is no indication that this fence system can be adapted to varied ground slopes, due to the fixed sizes and rectangular shapes of the fence panels, without again varying the louver spacing. Disassembly of this fence is simple: pull out the pin connectors and all the louvers fall to the ground; or, lift off the entire top row of louvers, followed by the second, third. . . etc. Re-use of the louvers requires complete reassembly of the fence.
The patent for "Interchangeable Fence Construction" (U.S. Pat. No. 3,454,262) describes another type of fence comprising discrete posts and wood panels. Its claim is for the interchangeability of prefabricated panels mounted between pre-installed posts. Design of the panel field may be infinitely varied, but the panel perimeter shape and size is always the same, making it interchangeable between posts. The design variation of the panel "field" is the basis of this patent, and panel design is not relevant to the present invention.
"Fence Structure" (U.S. Pat. No. 4,007,919) claims an "H"-shaped post and plastic-foam-filled, plastic, rectangular rails which fit into the slots of the "H" posts. The rail in the post slot is the primary claim, It is presumed that the post must be set into the ground for stability. This type of fence is only capable of straightline layout, but it is capable of adapting to changes of ground slope because the post slot is deep enough to permit vertical rotation of the rails in the slot before they are fixed or pinned to the post. There is no provision for making a gate within the system. Also, there is no provision for multi-fence intersections (branching to form new fence runs) because each post has but two, opposing, longitudinal slots, A multi-slotted post is a possibility, but that is not the primary claim, The slotted post is not germane to the present invention.
The"Modular Railing Assembly" (U.S. Pat. No. 3,491,984) claims a post and rail system which focuses on the joining of hollow metal or plastic post and railing components by means of a spline which fits and locks into both top of post (notched) and adjoining (hollow) rail (s). Each joint of this railing assembly system requires a number of components to achieve all the required connections. This modular assembly may be adapted to other than straightline layout, but adaptation to changes of ground or balcony elevation is difficult, if not impossible. A gate function is not part of this invention, nor is provision for branching at multi-fence intersections. This invention is primarily aimed at balcony or wall railing applications and is not relevant to the present invention.